With the rapid development of display technology, touch screens have been gradually and widely used in people's lives. According to the operation principle, the touch screens can be divided into the following types: a capacitive type, a resistive type, an infrared type, a surface acoustic wave type, an electromagnetic type, a vibration wave sensing type and a frustrated total internal reflection optical sensing type and the like. The capacitive touch screen has the advantages of high sensitivity, long life, high light transmittance, and the like. The capacitive touch screens can be further divided into a glass-glass (G-G) type and a single glass (OGS) type. The G-G type is to fabricate a sensor module on a normal glass and then attach it to a protective glass. The G-G type has the advantage that the manufacturing process is simple, but the disadvantages of it are a larger thickness, a lower transmittance and the like. The OGS type is to fabricate a sensor module directly on a tempered glass, which has the advantages of a simple structure, a thin thickness, a high transmittance and the like, and gradually becomes a mainstream technology. At present, the OGS type touch module occupies more than 60% of the market for the touch screens.